DESCRIPTION (Adapted from the application) The objectives of this core are to develop polyclonal and monoclonal antibodies useful for radioimmunoassay, for immunohistochemistry, and for immunoneutralization and to assist center members in the use of these antibodies. A second objective is to prepare radiolabeled and fluorescent peptides for use in radioimmunoassays, receptor binding, and receptor internalization studies. The core produces the antibody, develops the required assays, and provides the kits that are used by members at the center according to their own experiments. The core also provides teaching services for techniques and procedures including Western blot analysis, radio-iodination, ELISA, antibody production, antibody purification and Fc fragment production, RIA procedures, and fluorescence conjugations. These services will be used by CURE investigators, technicians, and postdoctoral fellows. In addition, the core will perform non-routine RIAs upon request. Antisera and monoclonal antibodies produced by the core are tabulated and are made available to center investigators. These available antibodies are listed on the CURE Web page and are made available to investigators outside the center. The space for this core consists of twin 500 square feet laboratories in the UCLA Division of Digestive Diseases adjacent to the office of Dr. Walsh. The laboratory is fully equipped for its current functions. Previously produced antibodies are readily distributed upon request after approval of the Director. Request for preparation of new antibodies requires consultation with the Director to determine the feasibility of the project and the most practical approach. A large number of center investigators, as well as scientists worldwide, have been provided core services, and many papers have resulted from interactions with this core. Between 1993 and June 1998, eighty-seven papers from the center have resulted from interactions with this core. During the period, there are 44 additional papers published by investigators who were not members of the CURE but who utilized the core services.